The invention relates to a method for examining the light and/or image transmission properties of an endoscopic or exoscopic system.
The invention furthermore relates to an apparatus for examining the light and/or image transmission properties of an endoscopic or exoscopic system.
Endoscopic systems are utilized in surgical procedures, in particular in minimally invasive surgery. In general, an endoscopic system has the components endoscope, light carrier, light source and camera, and possibly further components, such as for example a monitor for representing the endoscopic image. Exoscopic systems are also utilized in surgical procedures, but in open surgery. In general, an exoscopic system has the components exoscope, light carrier, light source and camera, and possibly further components as indicated above relating to the endoscopic systems. The invention will be described below for the sake of simplicity with reference to endoscopic systems, although it is to be appreciated that the following text also applies to exoscopic systems.
Within the meaning of the present invention, the endoscope may be a rigid or flexible endoscope. The endoscope, in typical construction, can have image transmission optics in its shaft and an eyepiece at the proximal end of the shaft. In this case, the imager and the objective of the camera are connected to the eyepiece by a camera head. The endoscope, however, can also be a video endoscope, in which the imager and the objective of the camera are integrated in the endoscope, for example in the distal end of the endoscope shaft. In this case, the eyepiece at the proximal end of the endoscope is omitted, and the endoscope and camera are in part merged into a single component. In general, a camera control unit also belongs to the camera. The light carrier is typically a light-guide cable which is connected at one end to the light source and at the other end to the endoscope. For endoscopes having directly coupled light carriers, the endoscope and light carrier are in part merged into a single component. The endoscope can, however, also include the light source, the light carrier and the camera as integrated parts.
In order to determine the operational capability of an endoscopic system for surgical treatment, the light and image transmission properties of the endoscopic system must be examined regularly.
To examine the light and image transmission properties of an endoscope, numerous approaches have already been proposed, for example in U.S. Pat. No. 5,820,547 A, DE 100 01 289 C1, U.S. Pat. No. 6,388,742 B1, EP 1 187 496 B1, U.S. Pat. No. 6,734,958 B1, U.S. Pat. No. 7,875,636 B2, U.S. Pat. No. 7,022,065 B2, U.S. Pat. No. 8,040,496 B2. The examination apparatuses described in said documents are indeed suitable for determining the light and/or image transmission properties of endoscopes, but owing to their complicated construction, said apparatuses come with disadvantages. They are relatively complex examination structures which are not suitable for examining an endoscopic system in the operating room and in particular cannot be used under sterile conditions.
Moreover, examination apparatuses and methods for ascertaining the properties of endoscopes for more complex endoscopic methods, such as for example for fluorescence endoscopy, are known, for example in DE 196 38 809 C2, DE 198 55 853 B4, EP 2 306 750 A1, EP 2 335 556 A1, EP 2 335 557 A1. Some of said apparatuses can be used under sterile conditions, if the measurement target used for the examination is designed to be able to be sterilized or autoclaved.
The apparatuses and methods disclosed in EP 2 335 556 A1 and EP 2 335 557 A1 allow the use of standard endoscopes for white light endoscopy in addition to endoscopes for fluorescence endoscopy. Here, the examination complexity is relatively low because the endoscopic camera is used as the measurement sensor such that the examination structure requires only a reflection measurement target and no other active measurement sensor. EP 2 335 556 A1 furthermore describes that the result of the examination method of the endoscopic system with respect to functionality or with respect to another property of the endoscopic system, and possibly the result of a subsequent or previous examination of the patient using the endoscopic system are stored in a database.
The disadvantage pertaining to the previously mentioned examination methods and apparatuses is that the examination allows merely knowledge regarding the endoscopic system as a whole (endoscope, light guide, light source, camera) to be gained. In the case of an error, more in-depth examinations on the components level must be carried out. Another disadvantage is that the measurement target must always also be sterilized for use in a sterile area.
DE 603 06 309 T2 describes a system and a method for providing information relating to an endoscope, wherein the system comprises a history information acquisition unit, which acquires an item of information about the use history of an endoscope, an estimation unit which carries out an estimation of a long-term change in the endoscope from first use to the current time on the basis of the acquired information, and a display unit which displays the result of the estimation over a rate of long-term change, which is preset for the endoscope. This system and this method can be used to estimate the quality and performance of an endoscope merely on the basis of empirical values in long-term use. However, no exact statement relating to the current operational capability of the endoscope or indeed of the endoscopic system as a whole can be made therewith. This can be reliably ensured only by an examination that is based on measurement.
In addition, clinicians demand to be able to examine the functionality of an endoscopic system in the operating room and if possible directly before the operation, i.e. under sterile conditions, without the measurement target used in the examination also having to be autoclaved in each case. It should be possible for the operating room personnel to carry out the quality test simply and quickly.
It should also be possible to obtain not only knowledge relating to the current endoscopic system as a whole, but also information relating to the state of at least those components that, owing to reconditioning steps such as sterilization and autoclaving, degrade over time. For example, the light transmittance of the light fibres inside the light carrier and in the endoscope decreases on account of the extreme stresses inside the autoclave over a multiplicity of reconditioning cycles.
Owing to the necessary reconditioning and the multiplicity of daily operations, clinics nowadays have a relatively large number of endoscopes and light guides so as to be able to guarantee an undisturbed operation process and optimum use of the operating room without downtimes owing to reconditioning. Moreover, many clinics also reprocess the camera heads with the image recorder and the objective of the camera by way of autoclaving, such that such clinics also posses a certain number of camera heads. A clinic can likewise have multiple light sources.
Accordingly, various component combinations, in particular endoscope/light carrier combinations, are used statistically over time. For a simple examination of a current component combination as a whole in terms of its quality of light and/or image transmission properties, it has hitherto been impossible to make statements relating to the performance of the individual components without the need to examine the components individually.